The inventive subject matter relates to electrical apparatus and, more particularly, to switchgear.
FIG. 1 illustrates a conventional medium-voltage switchgear unit 10. The switchgear unit 10 includes a housing 15 having a plurality of compartments defined therein, including a front compartment 20, a rear compartment 25, and a bus compartment 30. The rear compartment 25 and the bus compartment 30 are coupled to a plenum 40, which may receive heated gases from the other compartments. The bus compartment 30 has a plurality of input power buses 31 housed therein.
The front compartment 20 houses a variety of switchgear components, here shown as including a contactor 28 and a low-voltage sub-compartment 21 that houses circuitry and mechanisms for controlling the contactor 28 and other devices in the switchgear unit 10. The front compartment 20 also houses an input fuse assembly 23 that holds a plurality of fuses 24 and includes an input isolation switch 27. The fuse assembly 23 is mounted on a wall 22 that separates the front compartment 20 from the rear compartment 25. The fuses 24 fusibly couple the isolation switch 27 to the contactor 28 and other devices within the switchgear unit 10. The isolation switch 27 is configured to couple the fuses 24 to the plurality of input power buses 31 and is controlled by mechanical linkage extending from the handle mechanism.
The fuse assembly 23 includes top and bottom frame sections 23a and 23b. The top frame section 23a supports the isolation switch 27 and first fuse connection terminals for connecting to first terminals of the fuses 24. The bottom frame section 23b supports second fuse connection terminals for connecting to second terminals of the fuses 24, along with conductive contacts that are configured to mate with conductive contacts 26 extending from the contactor 28.